core: fix FileStateMachine->GetAllStatesForDevice()
core: fix FileStateMachine->GetAllStatesForDevice()

this was not working with permanent backend storage file
({devid}-bs-{timestamp}, used by imap backend)

Signed-off-by: Etienne CHAMPETIER <d24370f93c848f9b9e9043ebb082d433901eaa60@fiducial.net>

fmbiete/Z-Push-contrib,mta59066/Z-Push-contrib,Freeaqingme/Z-Push-contrib,RavenB/Z-Push-contrib